PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

MAF/ECU pinout help please

Old May 6, 2013 | 06:05 PM
  #1  
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Default MAF/ECU pinout help please

Hi All,

I am at my wits end!

I have an LS1 swapped into an Audi RS6 and all is going well. Ran it as stock LS1 normally aspirated last year on a 1 bar SD tune.

Over the winter the motor got stroked to 383, heads, cam and a pair of rear mount 3076 turbos. I want to switch to a MAF based tune and I have spent all day trying to figure out the MAF wiring to put in the blade style MAF. part # 15865791

I sent the following email to PSI Conversions earlier today and am awaiting a reply:

The harness has the following wires

Yellow
Black
Pink
Purple
Tan

I am reading the following on the lines with ign on

Yellow - GND
Black - 4.4V
Pink - Ground
Purple - +12v IGN
Tan - 4.4V

I have switched to the newer blade style MAF part # 15865791 and am trying to wire it in using information from here:

http://www.powrmax.com/94%20-%2006%2...onversion.html

However as you will see the voltages I am finding do not correlate with either the 01-04 MAF or the later style

believe you built this harness as a 5 wire MAF originally, but not for the latest MAF slot style.

I am hoping you can confirm the function of each wire in this harness i.e. something like below: (Note my descriptionsbelow I dont think are correct for the MAF pinout I need.

Yellow - GND - IAT sensor low ref
Black - 4.4V - IAT sensor signal
Pink - Ground - Ground
Purple - +12v IGN - IGN +
Tan 4.4V - MAF signal


Given the voltages I am seeing on the wires in the PSI conversions harness, I am starting to think the harness is wired incorrectly.

Does anyone here have the same MAF type of setup that could put a meter on the 5 wires and tell me what they see for voltages/continuity.

I believe I should be seeing the following, But I am totally confused right now so I might have things switched.

Yellow - MAF signal - ?4V?
Black - Low reference? - 5V?
Pink - IGN + - 12v
Purple IAT Sensor Ground -?
Tan - IAT Sensor Signal -?4V?

If anyone could measure what they have and LMK that would be awesome. The ECU is buried in this car so I am reluctant to pull it out, hwoever that is my next step to check which ECU pin each wire goes to, JIC they wired it wrong.

Thanks for your help

Timmmy.

P.s. Here is the car on the dyno the other day when we found we had no MAF

Old May 7, 2013 | 12:38 PM
  #2  
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Nobody?

OK after more investigation this is what I have found.

The harness is pinned incorrectly at the PCM (harness by PSI Conversions)


Below is what I have vs what it should be;

IAT Low reference = Yellow wire, pin 57 on red connector (should be purple) - Low reference
IAT Signal = Black wire, Pin 25 on red connector (should be Tan) - IAT Signal
Ground = Pink wire - This seems to be hooked into a common ground for the injectors and does not come direct to an ECU clean ground
Ign Volt 12+ = Purple wire, This also seems to be a shared 12v supply with the coils
MAF signal = Tan wire, Pin 31 on red connector (should be Yellow)

I suspect that both the ground wire and the IGN+ should be clean feeds from specific pins on the ECU. I am seeing pulsing in the power wire when the engine is running, I know the MAF is a freq signal so this may be why.

However with the MAF wired in to the correct pins on the PCM I do not get correct IAT or MAF functionality.

What are your thoughts on connecting the power and ground to specific pins on the PCM rather than a shared feed? Any particular pins?

Also what depinning tool is needed for these PCM connectors, I would like to get the correct wires into the correct spots/colors cleanly.

Does anyone have the ability to check what pins on their PCM (mine is 01-03) the power and ground lines are connected to.

Thanks

Timmmy
Old Dec 27, 2015 | 04:24 PM
  #3  
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back from the dead! But I can't find one other post specific to this MAF wiring.

Did you end up with a solution?

PM'd you too.
Old Dec 28, 2015 | 11:11 AM
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I just went through a whole ordeal of MAF wiring issues. PM me if you need help, I have a ton of verified information at home I can send you.
Old Feb 1, 2024 | 03:50 PM
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Default Maf/Iat

Originally Posted by Won-Ton
I just went through a whole ordeal of MAF wiring issues. PM me if you need help, I have a ton of verified information at home I can send you.
AF/IAT
Hi we have a Jackspania stand alone harness for a 2007 GMC Yukon 6.2 t56 and we cannot get the Maf/Iat to work either the engine will only run with the maf and cam sensor unplugged.
any suggestions
Old Feb 1, 2024 | 05:27 PM
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Won-Ton hasn't been here for 6 years. Check post dates.
Old Feb 3, 2024 | 03:05 PM
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MODERATORS NOTE: Because this is such an old thread, I am closing it. @1972NovaSS6.2l - you are welcome to start a new thread.


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